On the delta function broadening in the Kubo-Greenwood equation

Autor:	Bulanchuk, Pavlo
Rok vydání:	2019
Předmět:	Condensed Matter - Disordered Systems and Neural Networks Condensed Matter - Mesoscale and Nanoscale Physics
Druh dokumentu:	Working Paper
Popis:	Understanding DC electrical conductivity is crucial for the study of materials. Macroscopic DC conductivity can be calculated from first principles using the Kubo-Greenwood equation. The procedure involves finding the thermodynamic limit of the current response to an electric field that is slowly switched on, and then taking the limit of the switching rate to zero. We introduce a nonlinear extrapolation procedure executed in systems with periodic boundary conditions, which predicts conductivity close to the thermodynamic limit even for very small systems. The scheme also overcomes a large part of the usual ambiguities of the DC conductivity definition for finite systems. We numerically compare our method to the Landauer equation-based approach and find both techniques to be consistent with each other.
Databáze:	arXiv
Externí odkaz:	http://arxiv.org/abs/1907.12712 Zobrazit plný text záznamu View this record from Arxiv